[jordigh]

It would be, but GPLv3 states, in section 7, paragraph 4:

    If the Program as you received it, or any part of it, contains a
    notice stating that it is governed by this License along with a
    term that is a further restriction, you may remove that term.

So the author just didn't read GPLv3 and added meaningless additional restrictions.

[rjcz]

That is what I mean, basically :^)